Rotary-kettle kiln for drying and burning plaster stone, plaster, and other similar substances



Mar. 20, 1923. 1,449,326

G. JOURNET ROTARY KETTLE KILN FOR DRYING AND BURNING PLASTER STONE, PLASTER,

AND OTHER SIMI SUBSTANCES I Filed Aug. 1921 2 sheets-sheet l Mar. 20, 1923. 1,449,326 G. JOURNET ROTARY KETTLE KILN' FOR DRYING AND BURNING PLASTER STONE, PLASTER,

' AND OTHER SIMILAR SUBSTANCES Filed Aug. 10, 1921 2 sheets-sheet 2 avm-vvrae 6458/61. (/0 54 57 Fatentcd 211x20, was. i

TBS

RAFT

GABRIEL J OURNET, OF PARIS, FRANCE.

ROTARY-KETTLE KILN FOR DRYING AND BURNING PLAS'IER STONE, PLASTER, AND OTHER SIMILAR SUBSTANCES.

Application filed August 10, 1921. Serial No. 491,171.

To all whom it may concern Be it known that I, GABRIEL JoUnNE'r, a citizen of the French Republic, and a resi dent of Paris, France, have invented new and useful Improvements in a Rotary-Kettle Kiln for Drying and Burning Plaster Stone, Plaster, and Other Similar Substances, for which I have filed an application in France September 29, 1919, Patent No. 524,181, and of which the following is a specification.

The present invention consists in a rotary kettle kiln for the burning of plaster and also for the regenerating of waste or old plaster.

The kiln comprises, in general, two cylindrical kettles on horizontal axes, placed one above the other in one and the same furnace, each of which revolves slowly in a contrary direction from the other; interiorly the kettles are provided with helical wings for mixing the material and driving it towards the outlet situated in one of the ends of each kettle. The upper kettle is intended for drying the plaster-stone or plaster by the utilization of the hot gases derived from the furnace which heats the lower kettle in which the burning operation takes place.

The accompanying drawing shows, for the purpose of example, one method of carrying out the invention:

Fig. 1 shows a transverse vertical section through a furnace and the kettles therein:

Fig. 2 shows a longitudinal vertical section through the same.

The kettles a and a constituted by cylindrical bodies of sheet iron are furnished with rails b, and are supported by rollers c, the axes of which revolve in bearing secured by angle irons a buried in the masonry of the kiln d. The horizontal axes of the kettles a and a are located in different vertical planes so as to enable said kettles to be surrounded throughout the greater partof their outer surface by the hot gases from the furnace e. The rear wall of masonry of the furnace is provided at f with projections so as to prevent the gases from passing between the rear wall of the masonry and the kettle and compel the gases to follow the direction shown by the arrow F.

In one end of each kettle is an opening 9 fitted with a closure or door in the form of plug 72 the said opening 9 being provided for the removal of the material after drying or burning. In the centre of the opposite end is a circular opening 2' through which enters a feed-chute j surmounted by a hopper On the periphery of each kettle is. a toothed wheel Z gearing with a pinion m fixed to a shaft on. On each shaft m is a pulley driven by a crossed belt so as to cause the kettles a and a to revolve in opposite directions.

The lower shaft m is further provided with two other pulleys, one fast a and the other loose 02 which carry the belt driving both kettles.

Each feed-chute j is fitted with a regulator 0 for controlling the supply of material to the kettles, and also with a pipe 10 for carrying away the steam formed by the drying plaster-stone or plaster.

In the interior of each kettle, and diametrally opposite to one another, are fixed two helical wings g in sheet iron, running from one side to the other. The helical thread equals twice the length of the cylinder. The

breadth of the wings equals one-third of the diameter of the kettle; but, towards each end, it gradually decreases until, at the point where the said wings come in contact with the sides of the kettle, it is reduced to two-thirds of said breadth.

The helical wings perform the functions of mixing the material contained in the interior of the kettle and of driving it towards that end of the said kettle which is fitted with the discharge door.

For this purpose, in order to suit the direction of the rotation as hereafter indicated, the helix is dextrorsal for discharge on the right and sinistrorsal for discharge on the left.

By means of the decreasing width of the wings toward each end the said wings are prevented from producing any accumulation of the material against the sides of the kettle.

As regards the arrangement of the kettles and the furnace shown on the drawing, the rotation of the kettles is indicated by the arrows F and F that is to say, for an observer placed at the end of the kiln with the furnace on his right, the lower kettle revolves in the same direction as the hands of a watch, and the upper kettle in the contrary direction.

What I claim is:

1. A rotary kettle kiln for drying and burning plaster comprising a furnace, a cylindrical kettle located on a horizontal axis in said furnace, means for slowly rotating said kettle and a pair of diametrically opposite helical wings within said kettle, the width of each helical wing being approximately equal to one-third of the diameter of the kettleat :the middle part of said wing and gradually decreasing towards ends of the kettle, where it is reduced to approximately two-thirds ofsaid width.

2. A rotary kettle kiln for drying and burning plaster, comprising a furnace, two cylindrical kettles located one above the other on horizontal axes in said furnace, means for slowly rotating said kettles in opposite directions and a pair of diametrally opposite helical wings within each o'l said kettles, the width of each helical wing being approximately equal to one-third of the diameter of the kettle at the middle part of said wing, and gradually decreasing towards the sides of the kettle, where it is reduced to approximately two-thirds of said width.

3. A rotary kettle kiln for drying and burning plaster comprising a furnace having a front and rear Walls, a plurality of cylindrical kettles located within the furnace between said walls and in superposed relation, the alternate kettles rotating slowly in opposite directions, mixing and conveying wings within each kettle, and projections extending inwardly from the rear wall of the furnace adjacent the uppermost kettle whereby to cause the furnace gases to pass entirely around said uppermost kettle.

In testimony whereof I have signed my name to this specification.

GABRIEL J OU'RNET.

Witnesses J. .ARMENGAUD .Ainii, W. DnmivRIMoNT. 

